Fuel control system for fuel burning engines



March 1965 w. H. COWLES ETAL 3,

FUEL CONTROL SYSTEM FOR FUEL BURNING ENGINES Filed Sept. 2'7, 1954 m v m r/ m m m n wear. M W H M m \\\\\\k m u I mum Q w w \N N N Q m mm Q 1% mv 3 MHMWUAH IWHIHHH United States Patent 3,171,420 FUEL CONTROL SYSTEM FOR FUEL BURNING N N Warren H. Cowles, Detroit, Julius Alberani, Birmingham, and Raymond L. Ensinger, Detroit, Mich., assignors to Holley Carburetor Company, Detroit, Mich, a'corporation of Michigan Filed Sept. 27, 1954, Ser. No. 458,616 9 Claims. (Cl. 137-48) This invention relates to fuel control systems for engines of the fuel burning type.

It is an object of this invention to provide improved iheans for automatically regulating the flow of fuel to the engine during any preselected speed control setting to maintain the engine speed substantially uniform regardless of changes in operating conditions which have a tendency to affect the speed of the engine. It is another object of this invention to regulate the flow of fuel under pressure from a supply passage to a delivery passage through a valve controlled orifice and to also maintain the pressure differential between the two passages substantially constant. As a result, the flow of fuel under pressure from the supply passage to the delivery passage is proportional to the effective flow area of the orifice. In other words, the pressure drop variable is omitted from consideration and more accurate control of the fuel is assured.

It is still another object of this invention to provide a fuel regulating system with a control valve having pressure chambers communicating with the supply passage and having a movable member for controlling the effective area of the orifice in response to differences in pressure in the two chambers.

It is a further object of this invention to provide the fuel control system with an element movable in opposite directions in response to variations of the engine speed and with means operated by the element for establishing the pressure differential in said chambers required to operate the control valve member.

It is still a further object of this invention to provide a lost motion mechanical connection between the element and control valve member for actuating the latter in response to movement of the element in the event of failure of the pressure means.

The foregoing as well as other objects will be made more apparent as this description proceeds especially when considered in connection with the accompanying drawing, wherein:

FIGURE 1 is a diagrammatic sectional view illustrating a fuel control system embodying the features of this invention; and

FIGURE 2 is a sectional view taken on the line 22 of FIGURE 1.

InFIGURE l of the drawing the numeral 10 indicates a source of fuel and the numeral 11 designates a supply passage for the fuel. The fuel from the source 10 is conveyed to the supply passage 11 by a pump 12 of the positive displacement type having the intake side communicating with the source and having the discharge side communicating with the supply passage 11. Thus, fuel flows under pressure through the supply passage 11. The discharge end of the supply passage 11 communicates with the receiving end of a delivery passage 13 and the latter is connected to the fuel burner of an engine, not shown herein.

The flow of fuel under pressure from the supply passage 11 to the delivery passage 13 is regulated by a control valve 14 having a fixed cylindrical casing 15 and having a valve member 16 mounted in the casing 15 for sliding movement in opposite directions. The cylindrical casing 3,171,428 Patented Mar. 2, 1955 15 has ports 17 which communicate with the receiving end of the delivery passage 13 and also has orifices 18 positioned to communicate with the discharge end of the supply passage 11.

. The valve member 16 has a cylindrical enlargement 19 at the rear end for sliding engagement with the inner surface of the casing 15 beyond the ports 17 and has a second cylindrical enlargement 20 slidably engageable with the inner surface of the casing 15 adjacent the orifices 18. The cylindrical enlargement 2t) overlies the orifices 18 and is recessed as at 21 to provide openings which register with the orifices 18 in the left hand position of the valve member 16 as seen in FIGURE -1. The arrangement is such that rearward movement of the valve member 16 from its illustrated position progressively to the right de creases the effective areas of the orifices 18 and hence reduces the amount of fuel flowing fromthe supply passage 11 to the delivery passage 13. On the other hand, movement of the valve member 16 to the left from a position wherein the orifices 18 are closed by the cylindrical enlargement 20 progressively increases the effective flow areas of the orifices 18 to correspondingly increase the flow of fuel from the supply passage 11 to the delivery passage 13.

The flow of fuel under pressure from the supply passage 11 to the delivery passage 13 varies'in proportion to the effective flow area of the orifices 18 and the pressure drop across the orifices 18. In order to omit the pressure drop variable, provision is made herein for maintaining a substantially uniform pressure differential between the supply passage 11 and the delivery passage 13. For accomplishing this result, a bypass valve 22 is provided having a cylinder 23 and a valve member 24 slidably supported in the cylinder 23. The valve member 24 is in the form of a tube having the one end closed and having its other end open for communication with the supply passage 11. In addition, the valve member 24 has ports 25 through opposite side walls thereof and these ports register with an annular groove 26 formed in the adjacent wall of the cylinder 23. The annular groove 26 has a port 27 in concentric relationship to the valve member 24 and communicates with a chamber 28 which in turn is-connected to the source of fuel supply 11) by a passage 29;

The valve member 24 also has annular enlargements 30 at opposite sides of the ports 25 and slidably engageable with the inner surface'of the cylinder 23 at opposite sides of the groove 26 to normally prevent escape of fuel from the groove 26 through post 27. However, movement of the valve member 24 by the fuel under pressure in the supply passage 11 opens the port 27 and permits the fuel to return to the source of supply 10. Movement of the valve member 24 by the pressure of the fuel in the supply' passage 11 is resisted by a coil spring 31 acting on the closed end of the valve member 24 and arranged in a space32 which is connected to a delivery passage 13 by a passage 33. Thus, the pressure of the fuel in the delivery passage 13 supplements the force of the spring 31 to resist movement of thevalve member 24 by the pressure in the supply passage 11. With this arrangement, it will be noted that should the pressure differential between the fuel supply passage 11 and the delivery passage 13 become excessive, the valve member 24 is moved by the increased pressure in the supply passage 11 so that some 'ofth'e fuel isbypassed from the supply passage back to the source of supply 10. Thus, a predeterminedconstant pressure differential is maintained between the supply passage 11 and delivery passage 13 by the bypass valve 22.

The purpose of maintaining a predetermined uniform pressure differential between the supply passage 11 and the delivery passage 13 is to simplify as well as assure accurate control of the flow of fuel from the supply passage 11 to the delivery passage 13. As stated above, the valve 14 serves to regulate the amount of fuel admitted to the delivery passage 13 from the supply passage 11 and this valve is operated in response to variations in engine speed. As shown inFIGURE l, a pair of chambers 34 and 35 are respectively provided at opposite ends of the cylindrical enlargements of the valve 'member 16. The chamber 34 communicates with the supply passage 11 through a passage 36 having a restriction 37 therein. The chamber 35 is also connectedto the supply passage 11 by a passage 38 having a restriction 39 identical to the restriction 37. Thus, the pressure of fluid supplied to the two chambers 34 and 35 is equal. The pressure in the chamber 34 acts on the enlargement 19 tending to move the valve member 16 in a direction to increase the flow areas of the orifices 18 and the pressure in the chamber 35 acts on the enlargement 20 tending to move the valve member 14 in a direction to reduce the effective areas of the orifices 18. With this arrangement, the valve member 16 may be moved-in the casing to regulate the flow of fuel through the orifices 18 by creating a pressure differential in the chambers 34 and 35.

In accordance with this invention, the pressures in the respective chambers 34 and 35 are'relatively varied in response to changes in the engine speed. In this connection it will be noted from FIGURE 1 that the numeral 40 indicates a shaft which is driven by the engine and is connectedto a plate 41 for rotating-the latter. Carried by the plate 41 are centrifugally operated weights in the form of arms 42 having ends pivoted to the plate 41 adjacent the periphery of the latter by pins 43 having their respective axis extending perpendicular to the axis of the 'shaft 40. The pivoted ends of the arms 42 have extensions 44 which project inwardly and are operatively connected at their inner ends to a collar '45. The collar 45 is journalled on a shaft46 and is fixed againstmovement axially of the shaft 46. The arrangement is such that when the arms 42 swing outwardly in response to an increase in speed of rotation of the shaft 40, the collar 45 together with the shaft 46 is shifted to the right as seen in FIGURE 1 by the extensions 44, and when the arms 42 swing inwardly in response to a decrease in speed of the engine shaft, the collar 45 along with the shaft 46 is shifted to the left by the extensions 44.

The right hand end of the shaft 46 has a lost motion mechanical type connection with an extension 47 projecting from the valve member 16 of the fuel control valve 14 into a relatively low pressure chamber 48. The lost motion mechanical connection comprises a bell crank lever 49 having'an arm 50 pivoted by a pin 51' to the end of the shaft 46 and also pivoted by a pin 52 to the adjacent end of the extension 47 on the valve member16. The two pivots 51 and 52 are spaced from one another to enable limited relative axial movement of the shaft 46 and valve member 16. The. purpose of this lost motion mechanical connection will become apparent as this scription proceeds. 1

Referring again to FIGURE 1 of the drawing, it 'will' be noted that'the valve member 16 is formedwithtwo passages 53 and 54 therethrough. The passage 53 connects the chamber 34 to therelatively low pressure chamber 48 through a port 56, and the passage 54 connects the chamber 35 to the low pressure chamber. 48 through a port 55.. The port 55 is located in a position to be closed by the end of the shaft 46 when the latter is shifted. in response to an increase in speed of rotation of theengine shaft 40. The port 56 on the other hand isadapted to be closed by the other arm 57 of the bell crank lever 49 in response to a decreasein speed of rotation of the engine shaft 40. In this connection, attention is called 4 With the construction described above, it will be noted that should the speed of rotation of the engine shaft 40 increase for some reason, the arms 42 swing outwardly and shift the shaft 46 in a directionto close the port 55 I and open the port 56. As a result, the pressure in the chamber 34drops sufficiently below the chamber 35 to permit movement of the'valve member 16 relative to the valve casing 15. Such movement of the valve member 16 reduces the effective areas of the orifices 18 and, hence, reduces the amount of fuel introduced to the delivery passage 13. Should the speed of rotation ofv the engine shaft 40 decrease, the arms 42 swing in an inward direction to impart a shifting movement to the left to the shaft 46. Movement of the shaft 46 in such a direction opens the port 55 and also actuates the bell'c'rank lever 49 to close the port 56. Thus, the pressure of the fuel in the chamber 35 drops below the pressure of the fuel in the chamber 34 sufliciently to move the valve member 16 in a direction to thereby increase the effective areas of the orifices 18 and supply a greater amount of fuel to the delivery passage 13. Thus, the amount of fuel admitted to the delivery passage 13 is varied automatically in response to variations in the speed of rotation of the engine shaft 40. Due to the lost motionmechanical connection between the shaft 46 and the valve member 16, a certain amount of control of the valve 14 is possible even though the pressure system should become inoperative.

In order to enable presetting the speed of the engine,

manually operable control mechanism 58 is provided.

This mechanism comprises a cam 59, lever means 60 for operating the cam and a bell crank lever 61 operated by the cam 59. The bell crank lever 61 is pivoted by a pin 62 intermediate the ends thereof'for swinging movement and one arm 63 of the bell crank lever, is engaged by the cam 59. The other arm 64 of the bell crank lever is pivoted to a collar 65 mounted for sliding movement relative to the shaft 46. The collar 65 forms an abutment for the end of a coil spring having its other end engagement an abutment 67 on the shaft 46. Thus, the collar 65 is operatively connected to the shaft 46 by the coil spring 66 enabling the valve member 16 of the control valve 14 to be adjusted by the cam 59 to obtain a preselected engine speed. The spring 66 is preloaded by the cam 59 and serves to not only permit shifting movement of the shaft 46 relative to the speed setting mechanism but, in addition, resists outward movement of the centrifugal arms 42in response to an increase in speed ofthe engine shaft 40. Thus, the movement of the shaft 46 to in turn operate the control valve 14 is controlled by the force balance between the centrifugal force output of the arms 42 and the force applied by the spring 66.

What'we claim as our invention is:

. l. A motor comprising means defining a pair of pressure chambers, a movable member having piston portions movable in said chambers, motor control means having a movable part, said movable member having a pair of restricted passages terminating in a pair of outlet ports located adjacent each other and communicating respectively with said chambers, lost motion means connecting saidmovable part and said movable member including.

outlet valves controlling said outlet ports, means interconnecting said outlet valves so-that as either moves toward closed position the other moves toward open position, said lost motion means and movable member including abutment portions restricting relative movement between said'movable part and movable member in both directions, and means for admitting alcontinuous but restricted flow of fluid to both of said chambers.

2. A piston, a cylinder in which said piston is movable, said piston. having an extension located outside said cylinder, means for actuating said piston including a member movable in a direction parallel to the axis of said cylinder, said piston having a pair of passages extending from opposite ends of said piston to a pair of outlet ports located adjacent 'eachother on said extension, means providing acontinuous restricted flow of fluid under pressure into both ends of said cylinder, lost motion coupling means connecting said member and extension and'including-valve parts-movable respectively toward and away from said ports'to effect opposite. variations: of pressure at opposite ends ofsaid cylinder. to shift: said piston-and abutments between said coupling means andextension engageable to efiect mechanical movement of said piston-in either direction by-movement of said member.-- 1 1 .1 1 I 3. A cylinder, means providing a continuous restricted flow of fluid under pressure into both ends of said cylinder, a piston in said cylinder, said piston having an extension outside said cylinder, said piston having a pair of passages extending from opposite ends of said piston to a pair of outlet ports located adjacent each other on said extension, one of said ports being at the end of said extension and the other at a side of said extension adjacent the end thereof, means comprising a member adjacent said extension and movable parallel to the axis of said cylinder, a coupling element pivoted to said member and to said extension and having valving portions normally in partly closing relation to said outlet ports and movable respectively toward and away upon movement of said member in either direction to oppositely control pressure within end portions of said cylinder to cause said piston to follow said member, said valving portions being engageable with said extension to limit pivoting of said coupling element to effect mechanical coupling of said extension and member.

4. A cylinder, means providing a continuous restricted flow of fluid under pressure into both ends of said cylinder, a piston in said cylinder, said piston having an extension outside said cylinder, said piston having a pair of passages extending from opposite ends of said piston to a pair of outlet ports located adjacent each other on said extension, means comprising a member adjacent said extension and movable parallel to the axis of said cylinder, a coupling element pivoted to said member and to said extension and having valving portions normally in partly closing relation to said outlet ports and movable respectively toward and away upon movement of said member in either direction to oppositely control pressure within end portions of said cylinder to cause said piston to follow said member, said element including abutment portions engageable with abutment portions on one of said member and element to provide for mechanical movement of said piston by said element in the absence of fluid pressure.

5. A cylinder, means providing a continuous restricted flow of fluid under pressure into both ends of said cylinder, a piston in said cylinder, said piston having an extension outside said cylinder, said piston having a pair of passages extending from opposite ends of said piston to a pair of outlet ports located adjacent each other on said extension, means comprising a member adjacent said extension and movable parallel to the axis of said cylinder, a coupling element pivoted to said member and to said extension and having valving portions normally in partly closing relation to said outlet ports and movable respectively toward and away upon movement of said member in either direction to oppositely control pressure within end portions of said cylinder tocause said piston to follow said member, said valving portions being movable into engagement with said extension to limit pivotal movement thereof coincidental with full closure of either of said outlet ports to provide for mechanical movement of said piston by said element in the absence of fluid pressure.

6. Valve mechanism for controlling the rotative speed of an engine comprising a valve body having a cylinder therein closed at both ends, a piston-like valve slidable in said cylinder and having heads at opposite ends defining pressure chambers with the closed end portions ing a valving portion slidabl'e' across asidlport to control flow of fluid therethrough, a passage for'supplying fluid under pressure to said valveport, restricted-passages connecting said first mentioned-passage to'opposite ends of said-cylinder,- said piston-like valve having anextension slidably received'in an openingprovided atone end of said cyilnder, bleed passageseextending longitudinally of said extension and communicating respectivelygwith the, pressure chambers at .oppositeqends ,of said cylindfir; and. terminating in a pair of outlet bleed ports ocated adja; cent each other, speed responsive means adapted to be actuated by said engine and including a member movable adjacent said bleed ports, and lost motion bleed valve means connected to said member having rigidly connected bleed valve portions movable respectively toward and away from their associated bleed valve ports.

7. Valve mechanism for controlling the rotative speed of an engine comprising a valve body having a cylinder therein closed at both ends, a piston-like valve slidable in said cylinder and having heads at opposite ends defining pressure chambers with the closed end portions of said cylinder, a valve port in the side of said cylinder intermediate the ends thereof, said piston-like valve having a valving portion slida-ble across said port to control flow of fluid thereth-rough, a passage for supplying fluid under pressure to said valve port, restricted passages connect ing said first mentioned passage to opposite ends of said cylinder, said piston-like valve having an extension slidably received in an opening provided at one end of said cylinder, bleed passages extending longitudinally of said extension and communicating respectively with the pressure chambers at opposite ends of said cylinder and terminating in a pair of outlet bleed ports located adjacent each other, speed responsive means adapted to be actuated by said engine and including a member movable adjacent said bleed ports, and lost motion bleed valve means connected to said member having rigidly connected bleed valve portions movable respectively toward and away from their associated bleed valve ports and being engagea'ble therewith to effect mechanical movement of said piston-like valve by said member.

8. An engine speed governor comprising an engine speed responsive device, operator controlled means for adjusting said device to select an operating speed for the engine, servo-valve means controlled by said device, governor valve means having two opposed piston and cylinder devices connected thereto, a regulated pressure fluid source, a passage having a restriction therein connecting each of said piston and cyilnder devices to said source, a bleed passage connected to each of said piston and cylinder devices, said servo-valve means comprising separate valves controlling flow in said bleed passages, and operable by said speed responsive device to simultaneously vary the flow in said bleed passages in opposite sense, said servo-valve means and said engine speed responsive device being so constructed and arranged with respect to said governor valve means that a predetermined decrease in the pressure of said source causes said governor valve to become mechanically connected to said engine speed responsive device for the purpose of controlling the speed of the engine in an increasing and decreasing direction.

9. An engine speed governor comprising an engine speed responsive device, operator controlled means for adjusting said device to select an operating speed for the engine, servo-valve means controlled by said device, governor valve means having two opposed piston and cylinder devices connected thereto, a fuel pump, passage means connecting said fuel pump to said governor valve means, means responsive to pressure drop across said governor valve means to regulate the pressure of fuel supplied to said governor valve means, passages each having a restniction therein connecting each of said piston and cylinder devices to said passage means, a bleed passage conbleed passages in opposite sense, said servo-valve means and said engine speed responsive device being so constructed and arranged with respect to said governor valve means that a predetermined decrease in the pressure of fuel supplied to said governor valve means causes said governor valve meansfro become mechanically connected to said engine speed responsive device for the purpose of controlling the speed of the engine in an increasing and decreasing direction.

References Cited in the file of this patent UNITED STATES PATENTS Martin. -s Sept. 26, Imblumf Mar. 5,, Muller Apr. 28, Pfau "Feb. 29, Bou-rland Mar. 20, Neal Nov. 6, Orr Oct. 7, McCOur-ty et al. Apr. 7, Bevins Mar. 9, Leduc June 21,

Anderson Aug. 12, 

1. A MOTOR COMPRISING MEANS DEFINING A PAIR OF PRESSURE CHAMBERS, A MOVABLE MEMBER HAVING PISTON PORTIONS MOVABLE IN SAID CHAMBERS, MOTOR CONTROL MEANS HAVING A MOVABLE PART, SAID MOVABLE MEMBER HAVING A PAIR OF RESTRICTED PASSAGES TERMINATING IN A PAIR OF OUTLET PORTS LOCATED ADJACENT EACH OTHER AND COMMUNICATING RESPECTIVELY WITH SAID CHAMBERS, LOST MOTION MEANS CONNECTING SAID MOVABLE PART AND SAID MOVABLE MEMBER INCLUDING OUTLET VALVES CONTROLLING SAID OUTLET PORTS, MEANS INTERCONNECTING SAID OUTLET VALVES SO THAT AS EITHER MOVES TOWARD CLOSED POSITION THE OTHER MOVES TOWARD OPEN POSITION, SAID LOST MOTION MEANS AND MOVABLE MEMBER INCLUDING ABUTMENT PORTIONS RESTRICTING RELATIVE MOVEMENT BETWEEN SAID MOVABLE PART AND MOVABLE MEMBER IN BOTH DIRECTIONS, AND MEANS FOR ADMITTING A CONTINUOUS BUT RESTRICTED FLOW OF FLUID TO BOTH OF SAID CHAMBERS. 